Kinetic Modeling of Combined Steam and CO₂ Reforming of Methane over the Ni–Pd/Al₂O₃ Catalyst Using Langmuir–Hinshelwood and Langmuir–Freundlich Isotherms

Abstract

Combined steam and CO 2 reforming of methane (CSCRM) testing was used to determine the responses of CH 4 conversion, H 2 and CO yield, and CO 2 conversion at a temperature range of 500−1000 °C, (CO 2 + H 2 O)/CH 4 ratio of 1−3, and CO 2 /H 2 O ratio of 1−3, over the Ni−Pd/Al 2 O 3 catalyst in a fixed bed reactor. The Ni−Pd/Al 2 O 3 catalyst was synthesized through the sol−gel method, and its chemical and physical properties were studied using transmission electron microscopy, scanning electron microscopy, H 2 chemisorption, and O 2 -pulse titration methods. A kinetic model for the CSCRM reaction was also developed based on Langmuir−Hinshelwood and Langmuir−Freundlich isotherms by ignoring the deactivation reactions. The results showed that experimental H 2 yield values were closer to the modeled values compared to other cases. The proposed kinetic model resulted in the highest accuracy with a mean absolute relative residual of 8.52% in predicting experimental data with a presumption of the Langmuir−Freundlich approach for derivation and also applying fugacity instead of partial pressure in rate equations.

Fabrication of Silica‐Supported Al‐Doped ZnO and Its Use in the Elimination of the Toxic Organic Ingredients from Industrial Effluents

“…The Langmuir-Hinshelwood kinetics model explained the kinetics of photodegradation. [34] Because of the low amount of organic content, the Langmuir-Hinshelwood kinetics model is modified as. [35] -ln A=A0 ¼ kt (4)…”

Enhanced thermal stability and adsorption performance of MIL-53(Fe)@montmorillonite

“…Freundlich model was an empirical model used to describe heterogeneous adsorption systems, which described the exponential distribution of the active sites of heterogeneous adsorbents and their energy on adsorbate . The L-F equation, a kind of semi-empirical equation based on introducing the Langmuir equation into the Freundlich equation in exponential form for describing the surface heterogeneity of the adsorbent, could be applied to analyze data of adsorption (Batebi et al, 2021). For the more, in order to make up for the deficiency of the Freundlich equation, a semi-empirical Toth equation could also be applied (Kumar et al, 2021).…”

Combined steam and dry reforming of methanol over Fe‐Mn‐Cu / ZrO 2 catalyst to syngas formation: Study about kinetic and fuzzy model approaches

“…Based on the species involved in the CSDRM process, the equation of state (EoS) of PC-SAFT could be applied well to evaluate the behavior of phase equilibrium. [42][43][44][45][46] Thereby, it was used to precisely calculate the VLE state in our study. The pure components parameters and binary interactions for the mixture including carbon monoxide, formic acid, hydrogen, methanol, steam and carbon dioxide were achieved by the literature.…”

“…The pure components parameters and binary interactions for the mixture including carbon monoxide, formic acid, hydrogen, methanol, steam and carbon dioxide were achieved by the literature. [42][43][44][45][46]…”

“…The kinetic model parameters of CSDRM, MD and WGS reactions included the rate constants and equilibrium constants. Arrhenius equation (Equation 38) was used to illustrate the relation of the reaction rate constant to process temperature [45][46][47][48] :…”